Dim pLayerAsILayer
Set pMxDocument =Application.Document Set pMap =pMxDocument.FocusMap Set pLayer =pMxDocument.SelectedLayer pMap.MoveLayer pLayer, pMap.LayerCount- 1
End Sub
IMap接口的第十二个方法SelectByShape(Shape, env, justOne) （方法，从Layer中依靠一个图形的范围shape和一个选择的环境env来选择要素，而在所有图层中只从IFeatureLayer的图层中进行选择）
20. 关于IPropertySet接口(esriSystem)
IPropertySet接口的第一个方法SetProperties (names, values ) （方法，设置属性） IPropertySet接口的第二个方法SetProperty (name, value ) （方法，设置属性）
例子代码：
Dim pPropset AsIPropertySet Set pPropset = NewPropertySet With pPropset
.SetProperty\ .SetProperty\ .SetProperty\ .SetProperty\ .SetProperty\ .SetProperty\ End With
Dim pFactSDE AsIWorkspaceFactory Set pFactSDE = NewSdeWorkspaceFactory
Dim pWorkSpaceSDE AsIWorkspace
Set pWorkSpaceSDE = pFactSDE.Open(pPropset,Me.hWnd)
'Example of howtouseapropertysettoopenaPersonalGeodatabaseworkspace.
Dim pPropset AsIPropertySet Set pPropset = NewPropertySet
pPropset.SetProperty\
Dim pFactAccess AsIWorkspaceFactory Set pFactAccess = NewAccessWorkspaceFactory
Dim pWorkSpaceAccess AsIWorkspace
Set pWorkSpaceAccess =pFactAccess.Open(pPropset,Me.hWnd) 21. 关于IFeatureWorkspace接口（esriGeoDatabase）
IFeatureWorkspace接口的第一个方法OpenFeatureClass (Name) （方法，从一个要素工作空间打开一个要素，返回一个IFeatureClass类型的变量）
例子代码：
'This example opensashapefileasafeatureclass. Public Sub OpenFeatureClass_Example() Dim pWorkspaceFactoryAsIWorkspaceFactory
Set pWorkspaceFactory= New ShapefileWorkspaceFactory Dim pFeatureWorkspaceAsIFeatureWorkspace
Set pFeatureWorkspace =pWorkspaceFactory.OpenFromFile(\ Dim pFeatureClassAsIFeatureClass
Set pFeatureClass =pFeatureWorkspace.OpenFeatureClass(\ MsgBox \ \ states\
End Sub
22. 关于IWorkspaceEdit接口（esriGeoDatabase）
例子代码：
Public Sub WorkspaceEdit()
Dim pWorkspaceFactoryAsIWorkspaceFactory
Set pWorkspaceFactory= New esriDataSourcesGDB.AccessWorkspaceFactory Dim pFeatureWorkspaceAsIFeatureWorkspace
Set pFeatureWorkspace = pWorkspaceFactory.OpenFromFile(\ Dim pFeatureClassAsIFeatureClass
Set pFeatureClass =pFeatureWorkspace.OpenFeatureClass(\ Dim pWorkspaceEditAsIWorkspaceEdit Set pWorkspaceEdit =pFeatureWorkspace Dim pFeatureAsIFeature Dim iResponseAsInteger
Dim bHasEditsAsBoolean pWorkspaceEdit.StartEditingTrue pWorkspaceEdit.StartEditOperation Set pFeature =pFeatureClass.GetFeature(1) pFeature.Delete
pWorkspaceEdit.StopEditOperation
iResponse = MsgBox(\ If iResponse =vbYesThen pWorkspaceEdit.UndoEditOperation End If
pWorkspaceEdit.HasEditsbHasEdits If bHasEditsThen
pWorkspaceEdit.StopEditingMsgBox(\ End If
End Sub
在实际问题中，如果有多次操作需要更改Feature的时候，切记要将操作对象重新赋值，不然在pWorkspaceEdit.StopEditing(true)的时候会出现错误，报错代码为-2147467259。
（详细代码可见WindowsApplication6的代码，其中详细操作了对字段的编辑过程，其中涉及到很多对字段Field的方法 Add(Field)，Delete(Field)，get_value(object value)，set_value(intindex, object value)等等操作，其中还涉及到Feature经过ICursor类选取与经过FeatureClass类的方法GetFeature选取的区别）
23. 关于IWorkspaceFactory接口（esriGeoDatabase）
IWorkspaceFactory接口的第一个方法Open (ConnectionProperties, hWnd ) （方法，从一个工作工厂打开一个工作空间，并返回IWorkspace类型的变量，方法中的第一个参数ConnectionProperties是IPropertySet接口的变量）
例子代码：
Dim pSdeWorkspaceFactoryAsIWorkspaceFactory Dim pSdeWorkspace AsIWorkspace Dim pConnectionPropertiesAsIPropertySet
Set pConnectionProperties =NewPropertySet With pConnectionProperties .SetProperty\ .SetProperty\ .SetProperty\ .SetProperty\ .SetProperty\
End With
Set pSdeWorkspaceFactory =NewSdeWorkspaceFactory
Set pSdeWorkspace = pSdeWorkspaceFactory.Open(pConnectionProperties,0)
IWorkspaceFactory接口的第二个方法OpenFromFile (fileName, hWnd ) （方法，从一个路径打开一个工作空间，并返回IWorkspace类型的变量）
例子代码：
Dim pSdeWorkspaceFactoryAsIWorkspaceFactory Dim pSdeWorkspace AsIWorkspace
Set pSdeWorkspaceFactory =NewSdeWorkspaceFactory
Set pSdeWorkspace = pSdeWorkspaceFactory.OpenFromFile(\
24. 关于ITopologicalOperator接口（esriGeometry）
例子代码： Share a linesegment
ThissampleusesITopologicalOperator::Intersecttodotheequivalentofaselectbylocationwiththesharealinesegmentoperator.
Public Sub ShareLineSegment()
Dim pMxDocAsIMxDocument Set pMxDoc =ThisDocument Dim pMapAsIMap Set pMap =pMxDoc.FocusMap
Dim pFL1AsIFeatureLayer,pFL2AsIFeatureLayer Set pFL1 =pMap.Layer(0) 'firstlayerofmap Set pFL2 =pMap.Layer(1) 'secondlayer Dim pF1AsIFeature,pF2AsIFeature
Set pF1 =pFL1.FeatureClass.GetFeature(1)'getfeaturewith infirstlayer'sfeatureclass
Dim pfsAsIFeatureSelection Set pfs =pFL2 Dim idAsLong id =pfs.SelectionSet.IDs.Next 'getfirstidinselectionsetanactualfunctionwouldprobablyloopovertheselection
Set pF2 =pFL2.FeatureClass.GetFeature(id)'thisisline2
'isthereanintersectionbwthetwofeatures Dim pTopoAsITopologicalOperator
Set pTopo =pF1.Shape'storetheline1shapeinthetopoop If NotpTopo.IsSimpleThenpTopo.Simplify Dim pGeomAsIGeometry
Set pGeom =pTopo.Intersect(pF2.Shape,esriGeometry1Dimension)'getintersectionwithline2 If pGeom.IsEmptyThen
MsgBox \ Exit Sub End If
'pGeomnowcontainstheintersectionofpf1andpf2 'becausedimension =esriGeometry1Dimension 'itisageometryoftypepolyline
'iftheintersectionofthetwofeaturesconsistedofapointorpointspgeomwouldbeempty 'wecoulduseITopologicalOperator::Intersectwith0dimensiontofindaboutthosepoints
'ifpGeomcontainsonlytwoverticesthentheintersectionisasimplelinesegment '3verticesmeansit'sapolylinewithtwosuccessivesegments
'>3 means we haveseveral segments or a polyline or a combination of these Dim ppc1AsIPointCollection Set ppc1 =pGeom Dim lAsLong,gAsLong l =ppc1.PointCount If l =2Then
MsgBox \ ElseIf l =3Then
MsgBox \
ElseIf l > 3 Then
Dim pGeomCollAsIGeometryCollection Set pGeomColl =pGeom g = pGeomColl.GeometryCount
MsgBox \ End If
End Sub